Which is the first step in the Darwin-Dana-Daly theory of atoll formation?

The first step in the Darwin-Dana-Daly theory of atoll formation involves the emergence of an oceanic volcano from the sea surface. This process marks the beginning of atoll development. Initially, volcanic islands are formed by underwater volcanic eruptions that build up the island above the ocean surface. These islands provide a foundation for coral development.

Once the volcano emerges, coral reefs begin to grow around the island, eventually leading to the formation of a fringing reef. Over time, as the volcano erodes and the island subsides, the coral continues to thrive, leading to the formation of a barrier reef, and ultimately resulting in the atoll structure that is characterized by a ring of coral surrounding a lagoon. This progression is central to understanding the geological and ecological dynamics involved in atoll formation.